The Trade Union was a Republic commence guild, trade cartel, megacorporation and lobbying group that was founded in 5 ABY as an association of business and trade groups with it's own commercial trade fleet.
It grew to dominate entire star systems and all major trade routes, and possessed a formidable and private military. Towards the end of the Republic, It would become increasingly dominated by the commence-sawy Twi'leks.
The Trade Union was a shipping corporation and cartel, it made deals with Czerka Corporation and spice traders in order to form it's own private military to accomplish their Sith-influenced aims, it was originally controlled by a directorate, which was led by a commanding Viceroy.
Tw'leks were very influential in the leadership of the Directorate. though the Union only became a Twi'lek monopoly in 33 BBY when the Trade Union Directorate was murdered, leaving Viceroy Nute Gunray. He proceeded to fill up the vacancies with his Twi'lek puppets, some of whom later comprised the Occupation Council that took control of Pau City after the Utapau invasion.